For several aspects of digital picture or digital image processing and their applications, for instance in consumer or customer devices, it is important for the respective processing or even for the application to have an estimate of the respective noise level contained in the respective images, the pictures or the respective signals conveying the same. This is in particular important for so-called noise compensation processes, for instance in image enhancement processing.
In many cases, incomming signals are somewhat distorted by the communication channel or by the receiving equipment, for instance by clipping the incomming signals if the signal's amplitude is too low or to high.
Therefore, many known estimation methods for statistical properties or noise estimation methods are do not derive statistical properties for the incomming signals and only describe the respective already distorted dignal's version and consequently give only very limited information with respect to the original and undistorted incomming signals.